The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: adunham1 on 18.04. 2020 16:08

Title: Chamfered washer behind oil pump worm gear?
Post by: adunham1 on 18.04. 2020 16:08
Hi everyone,

Working on assembly of my A10 engine and I've come across part 67-0645 (https://www.classicbritishspares.com/products/bsa-crankshaft-timing-side-oil-pump-gear-wasaher-67-0645-71-2500-1962-72-a50-a65) and wondered... which direction does the chamfer face? Inward towards the timing gear or outward towards the worm gear?

Thanks for any help!
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: berger on 18.04. 2020 19:30
chamfer to face gear to clear step on crankshaft
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: beezermacc on 19.04. 2020 08:15
This is sometimes described as a 'soft' washer. Its purpose is to provide a bit of a cushion between the gear and the worm as it is not good engineering practice to clamp brittle components tightly against each other.
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: berger on 19.04. 2020 09:52
beezermacc also not to bang two hammer heads together and get told off by dad when I was a young en *bash*
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: Greybeard on 19.04. 2020 14:30
beezermacc also not to bang two hammer heads together and get told off by dad when I was a young en *bash*
A friend blinded himself in one eye when a chunk of metal pierced his eye when he used a hammer to knock a claw hammer under a nail.
We all take chances but occasionally our luck runs out.
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: RDfella on 19.04. 2020 16:58
Heard about not using a hammer on a hammer myself, but confess to doing it fairly often. When removing a propeller from a boat there's not much room; using a puller doesn't always work and usually requires removing the rudder as well. Now, swinging a lump hammer at a prop will rarely arrive where it's needed on the boss and will most likely cause serious damage. My way is to rest a ballpein hammer against the boss and give it a hefty swipe with a large lump hammer. Works most of the time. Never had any shards flying about, but I agree glasses or safety glasses are recommended. Just why two hammers is regarded as a risk but not a hammer on an anvil (which is pretty hard) puzzles me.
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: bsa-bill on 19.04. 2020 17:09
Quote
but not a hammer on an anvil (which is pretty hard)

know what you mean RDfella, but wonder about just how hard anvils are, I've seen quite a few in my time and they certainly "ring" when tapped but I've also noted a few that had bent! in places (like the end of the horn).
I loved to hear a smith using an anvil, always wondered though why the intermediate taps (sometimes two or more between striking the workpiece), possible a fatigue lessening method?
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: RDfella on 19.04. 2020 17:33
Ah, those 'intermediate taps'. Maybe same as blipping the throttle before the race light turns green? A sort of 'getting ready' for the actual action?  *bright idea*
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: ellis on 19.04. 2020 20:15
Is tapping the Anvil not a way of keeping the hammer at the right angle to work the metal.

ELLIS
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: muskrat on 19.04. 2020 21:05
Exactly the reason I'm blind in the right eye.  *sad*
Cheers
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: berger on 19.04. 2020 21:31
shit musky *sad2* glad I listened to dad, I was making them bounce off each other and he gave me some good advice
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: Greybeard on 19.04. 2020 22:40
I'm sure an anvil is not hardened.
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: berger on 19.04. 2020 22:53
greybeard they are forged and have a hard face, but not as hard as a hammer face as I understand it. so hammer on anvil is two differences of hard. hammer on hammer is same hardness and its not a good idea to bash them together as I was doing *bash*
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: adunham1 on 20.04. 2020 01:12
Thanks, everyone! Went ahead and fitted it inwards and moved on. Was able to get the SRM pump and inner timing case on.

The engine has been sitting apart since July of last year, so it's really nice to make some progress and see some light at the end of the tunnel! The goal is to have it done and back together before July. Otherwise I'll have spent a year (and too much money) only working on the engine...  whoops.
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: bsa-bill on 20.04. 2020 10:25
HI - wondering how the pump is held on, are those studs or nuts and are they supplied by SRM (looks nice)
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: berger on 20.04. 2020 10:40
I think they are those allen head or tourqsey whatsit bolts thingys, srm supply them, but I won't be using them on the berger build, studs all the way in ally
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: Butch (cb) on 20.04. 2020 11:27
Quote
but not a hammer on an anvil (which is pretty hard)

know what you mean RDfella, but wonder about just how hard anvils are, I've seen quite a few in my time and they certainly "ring" when tapped but I've also noted a few that had bent! in places (like the end of the horn).
I loved to hear a smith using an anvil, always wondered though why the intermediate taps (sometimes two or more between striking the workpiece), possible a fatigue lessening method?


https://www.youtube.com/watch?v=e4Ao-iNPPUc
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: bsa-bill on 20.04. 2020 11:39
oh my I used to drive a Massey like that
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: adunham1 on 20.04. 2020 15:15
HI - wondering how the pump is held on, are those studs or nuts and are they supplied by SRM (looks nice)

Hi Bill, they are Allen head bolts and split washers supplied by SRM with the pump; along with a new gasket.
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: ellis on 20.04. 2020 19:13
They are domed Allen cap screws. Click on the picture and all will be revealed.

ELLIS
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: trevinoz on 20.04. 2020 22:20
Button Head, I think.
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: Minto on 05.05. 2020 09:27
Havin just checked all the bits I've stripped off my engine, I don't have one of these shamfered washers between the worm gear and crank pinion. Should all A10 engines have this washer?
Cheers
Jase
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: Swarfcut on 05.05. 2020 09:44
 Jase.. Quick answer....Yes.   Depending on previous treatment, you may find the inner face of the hardened worm a bit ragged. This washer serves to position the worm above the oilpump drive spindle and provide a more even clamping force against the timing pinion, rather than just gouging into it.  Chamfer goes towards the timing pinion to clear the radiused change of shaft diameter, as already noted.

  Never considered if the original part was hardened, see earlier posts in this thread, but you can bet many motors are happily running around with a plain washer from the useful box. Any washer is better than no washer, so take your choice as to how you source one.

 Swarfy.
Title: Re: Chamfered washer behind oil pump worm gear?
Post by: Minto on 06.05. 2020 02:06
Thanks for the info Swarfy, got one ordered from Dragonfly, along with a couple of nuts n bolts for my "really useful" tin.
Cheers
Jase